Method of cutting laminated glass



Pa'teniezl Apr" 1, @930 min."

IPETER A. MCCULLOUGH, 0E PETTSBURGH, PENNSYLVANIA METHGD 0F CUTTINGLAMINATED GLASS 1N0 Drawing.

The invention relates to laminated glass, ccmmonlv called in the artcomposite glass, and the object is to provide a method of proclucingpieces oi predetermined; shape and 5 size from large sheets by a sittingoperation which is simple, inexpensive as compared to price "practice,produces pieces or" exact size, and which is readily practiced by thoseskilled in cutting ordinary glass end with the 1c same types of toolsemployed for that pur pose Laminated glass of the type hereincontemplated comprises two or more superposed layers oi? glass having atransparent non-frenlc gible binder interposed between and adherto theaccent surfaces of the glass. The binders generally used such pyrcxylinor A celluloid, possess suficient iietci" ility and. te-

=citjy to the pieces cf "less in posi- 131 when is crsckeci er hroirec.by shock thus conferring to such aerl glass its see-c lied m-shatteringprope ies.

Jresses the ethics to 131m "crown prevents 1 efers rec iiises special Il upoi my clis: s i LUECl e seine icic- The bind- Slime 1t s practice ofthe is es oi is scored the customary menisci", with e themoccl orApplication filed October 2, 1928. Serial life. 309,898.

the like, to outline the desired shape, The scored lines are disposed toprovide a piece of correct, or substantially correct size when the glassis broken thereelocg, just as in reg uler glass cutting practice In someinstances scoring of one surface will suflice but it is sometimesdesirable to score both surfaces,

the scored lines being opposed on the two s11rfaces, as wil be readilyunderstood After outlining the shape, the glass is subiecteol to such areduced temperature that the binder becomes brittle like the glass, whenit may be broken, or in the parlance of the trade out along the scoredlines of Weakness substantially as if it were integral glass. Thescoring may be done after the chilling, but is preferably dcne first, aswill be readily understoooiv,

Various means be used to cool the glasses to the proper reducedtemperature, the essential thing being that the glass is cooled at leastto the point Where the binder becomes brittle. For ersmple the scoredglass sheets may be placed in a. re L 'eretf chamber containing e iiuiclcooled by expansioc. of a suitable liquid refrigerant circulated.through pipes or coils disposed therein. For thin. laminated glass, themay be sir, Wlliifi in case of thick or with large erticies, the fluidmay be mcohol er other liquid which "Wi 1 not freeze at tempec atiireemployed. Likewise, the scorecl. glass be pieced in coritect with thesurfece of frozen liquids or other so he ing bcdies ccoleci to theproper tempers "es, as by refrigerating coils embedded therein usingsuch a solidi-contact procedcre it will usucily be desirable toprelimiceriiy coci tl glass, as by exposure to e r-e'irigerst Krnosphere before pie glass in is contact with the chilling surface Anysuitable refrigerant wh ch. will c heat-er. bringing fluid er c 1" bodythe necessary recmceci tem. sy be for example, such as lie .c accuseclififereiit binders ere used 1. composite giess, it ll'dti po an exacttemperature ts Wei s must be ccolecl order to be cut by t ess, but thattemperature is quickly em eesily that range per l dei'zerminahle foreach hinder. Since temperlznrc es low -300 F may he obtained by airrefrigeration it is possible to produce any lllgllel' temperaturereadily and ts eznbriiaizll. any

binders heretcxo After the l" nic hed has been properly chilled ii; 0 enin the same manner as ordinary by the application stresses "to cause it;lo :lracture the scored lines of Weakness, or by any o'cher method cableto brittle hard material like g g-less I claim:

1. The method of cutting laminated glass to size comprising chilling"the glass render it brittle throughout, While chilled breaking theglass to. form an accurately SlEJBfl piece.

2. The nieiihod oi culling laminzded to size comprising immersing theglass in a fluid at a temperature at which the binder becomes brittle,and breaking glass W the binder is brittle lo form an accurately sizedpiece.

3. The method of making sized pieces from laminated glass comprisingscoring the surface thereof to outline the desired piece chill in g saidsheet, and hile chilled breaking the glass along said. scoringsq i. Themethod of cutting sized pieces from laminated formed from e plurality oflayers ol' glass having a flexible hinder inter-- posed between adjacentsurfaces, comprising scoring the outer surface thereof to outline a thedesired iece, cooling the sheet to a point Where said inder becomesbrittle, end while chilled breaking the glass along said scored lines,

5. lhe method of cutting sized. pieces from laminated glass formed froma plurality cl? layers of glass having a flexible hinder interposedbetween adjacent surfaces comprising forming scored lines of weakness onthe outer surface of a sheet of said glass, cooling" said glass torender said hinder brittle, and While cooled. breaking the glass alongsaid lines of Weakness" In estimon whereof, ll sign my name PETER AMCJULLOUGH.

